/*
 * Copyright 2005 The Apache Software Foundation.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at 
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, 
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 
 * See the License for the specific language governing permissions and 
 * limitations under the License.
 */

package javax.jdo.spi;

/**
 * This interface is implemented by classes that can be detached from the
 * persistence context and later attached. The interface includes the 
 * contract by which the StateManager can set the object id, version,
 * BitSet of loaded fields, and BitSet of modified fields 
 * so they are preserved while outside the persistence environment.
 * <P>The detached state is stored as a field in each instance of Detachable. 
 * The field is serialized so as to maintain the state of the instance 
 * while detached. While detached, only the BitSet of modified fields 
 * will be modified. The structure of the Object[] jdoDetachedState
 * is as follows:
 *  <ul><li>jdoDetachedState[0]: the Object Id of the instance
 * </li><li>jdoDetachedState[1]: the Version of the instance
 * </li><li>jdoDetachedState[2]: a BitSet of loaded fields
 * </li><li>jdoDetachedState[3]: a BitSet of modified fields
 * </li></ul>
 * @version 2.0
 */

public interface Detachable {

    /** This method calls the StateManager with the current detached 
     * state instance as a parameter and replaces the current detached 
     * state instance with the value provided by the StateManager.  
     * @since 2.0
     */    
    public void jdoReplaceDetachedState();
}